1. Field of the Invention
The present invention relates to a memory device including electrically rewritable non-volatile memory cells, and more particularly, to a non-volatile memory device, in which a variable resistive element is used as a memory element to store the resistance thereof as data, and a method of reading the data from the non-volatile memory device.
2. Description of the Related Art
A resistive random access memory (ReRAM) that nonvolatily stores resistance information of an electrically rewritable variable resistive element has been known as a nonvolatile memory device. A memory cell of the ReRAM includes a variable resistive element having a recording layer made of a transition metal oxide. The relationship between the voltage of a column selecting line and the voltage of a row selecting line when storing status is read is disclosed in JP-A-2006-66052, for example.
It is preferable to arrange memory cells at the intersections of the column selecting lines and the row selecting lines in order to manufacture a high-density ReRAM at low manufacturing cost. In view of easy operation, a memory cell, in which a diode element is connected in series to a variable resistive element, has been used (refer to a nonpatent literature: Y. Hosoi et al., “High Speed Unipolar Switching Resistance RAM (RRAM) Technology”, IEEE International Electron Devices Meeting 2006 Technical Digest, pp. 793-796, for example).